How to fill joints in dome patio timber lining?

[Darrin]

I have utilised 6mm marine ply to line my steel frame and tin dome patio being 6x17 metres.

Can you suggest what to use between the timber joints to eliminate the expansion cracking due to changes in temperatures.

I have tried the timber putty but this cracked under the recent temperatures in Perth.

 

[EricL]

Hello @Darrin 

Welcome to the Bunnings Workshop community. It's sensational to have you join us, and thanks for sharing your question about what filler to use between your plywood panels.

I propose using Selleys 430g White No More Gaps Exterior Gap Filler. It's suitable for use on timber and synthetic weatherboards, as well as brick and concrete, masonry, ceramic tiles, glass and aluminium. Plus, it can be painted over once it cures. I recommend testing a section first to make sure that it can withstand the heat that your patio roof is generating. If all goes well then you can commit the rest of the boards in your ceiling.

Let me call on our experienced members @Dave-1 and @Nailbag for their recommendations.

If you need further assistance, please let us know.

Eric

[Nailbag]

Hi @Darrin 

My go-to product to cover timber joins has been this 30mm x 8mm rounded edge cover strap. I don't use any glues just brad it into place. Its neat and allows plenty of coverage for any expansion.

Hope this helped. Nailbag

[Dave-1]

Morning @Darrin 

I would take the same track as what @Nailbag has suggested and use some timber trim, and for the same reasoning. Id go for a wider trim to help make it "blend" to the eyes with the rounded edge that Nailbag has suggested.

If you dont want a trim to show then @EricL's suggestion and "testing" first is my Plan B option.

Is the issues accross the roof or just in the one spot you have shown? Ivegot it in my head one day to do this to a van and the only flexible solution was trim, I have thought of using Boyle 915 x 75 x 1mm Hobby Wood Sheet and have it installed offset, so one side is 30mm over the join and 45mm is over the wood. The 45mm is then glued to the timber. Expansion wouldnt be a worry as it would slide under the non joined face. Only a theory But may be worth a try if you want the roof to be as smmoth as possible. I would glue this as think anything going through the 1mm thick would tend to split it.

Dave